Truck was running good at WOT I was bumping the boost and after 13lbs at WOT it start like having a backfire and airfuel looks good around 12.0 I don?t know if it wants more leaner. Change spark plugs and doing the same thing. What AFR are ya running on around 15 lbs??
Truck it?s a 5.3, boost cam 76mm turbo, LT4 fuel system with external fuel pump, e85 on meth.